Dr Victor Rosenfeld detected alpha waves in the vast majority of fibromyalgia patients while the patients were sleeping, but did not in those without fibromyalgia, reports Savannah Morning News.

“Even though people with fibromyalgia are technically asleep, their brain waves look more like they’re awake,” Rosenfeld said. “In essence, people with fibromyalgia are pulling an all-nighter every single night.”

Such a finding explains why most fibromyalgia patients often report feeling tired, fatigued, achy and unfocused, he said.